Cam′phor, Commercial (Refined)

Syn. White camphor ; Campho′ra , B. P. Prep. 100 parts of crude camphor are mixed with 2 parts each of quick-lime and animal charcoal, both in powder, and the mixture is placed in a thin, globular, gla ve el, sunk in a sand bath. The heat is then cautiously applied, and the ve el gradually and carefully raised out of the sand as the sublimation goes on. When the proce is complete, the subliming ve el is removed and allowed to cool. Obs. The whole proce of refining camphor requires great care and experience to ensure its succe . If conducted too slowly, or at a heat under 375° Fahr., the product is found to be flaky, and consequently unsaleable, without remelting or subliming. An improvement on the common method is simply to sublime the above mixture in any convenient ve el furnished with a large and well-cooled receiver, and to remelt the product in close ve els under pre ure, and to cool the liquid ma as rapidly as po ible. Prop., . A white, semi-crystalline solid, very volatile at common temperatures; freely soluble in alcohol, ether, bisulphuret of carbon, benzol, oils, and acetic acid, and sufficiently so in water (about 1 1 ⁄ 4 gr. to 1 oz.), to impart its characteristic smell and taste; 100 parts of alcohol (sp. gr. ·806) di olve 120 parts of camphor; concentrated acetic acid di olves twice its weight of camphor; average sp. gr. ·990. It fuses at 347°, boils at 400° Fahr., and when set fire to, burns with a bright flame. It evaporates slowly at ordinary temperatures, and crystallises on the inside of bottles. While floating on water it undergoes a curious rotatory movement. Uses, . Camphor is sedative, narcotic, anodyne, diaphoretic, and anaphrodisiac. Dose , 2 to 10 gr. in the form of pill or bolus, or made into an emulsion with yolk of egg, mucilage, or almonds. In overdoses it is poisonous. The best antidote is opium or wine, preceded by an emetic. It is also used externally in ointments, liniments, and embrocations. Camphor is frequently put into wardrobes and clothes-trunks, to keep away insects; it is used to make the white stars and fire of the pyrotechnist; and by the varnish-maker to increase the solubility of copal and other gums. Mixed with six times its weight of clay, and distilled, it suffers decomposition, and yields a yellow, aromatic, volatile oil, smelling strongly of thyme and rosemary, which is much used by the wholesale druggists and perfumers to adulterate some of the more costly e ential oils, and by the fancy soap-makers to scent their soaps. Camphor may be beaten in a mortar for some time, without being reduced to powder, but if it be first broken with the pestle, and then sprinkled with a few drops of rectified spirit of wine, it may be readily pulverised. By adding water to an alcoholic or ethereal solution of camphor, this drug is precipitated under the form of an impalpable powder of exquisite whitene . Tests. Pure camphor is entirely soluble in rectified spirit, oils, and strong acetic acid; a fragment placed on a heated spoon or in a warm situation will wholly disappear, and the evolved fumes will be highly fragrant (camphoraceous), and be free from an acid or terebinth in ate odour. In an alcoholic solution of natural camphor ammonia gives but a slight precipitate, which is di olved on shaking the mixture; a similar solution of artificial camphor under the like treatment gives a flocculent precipitate, which remains undi olved. See Camphor, Factitious ( below ).